Answer: <em>The </em><em>alkali metals</em><em> reactivity is generally higher than the alkaline earth metals. </em>
Explanation: <em>This makes the alkaline earth metals with their two valence electrons less reactive than alkali metals with their one valence electron.</em>
<u>Alkali metals is ns1 and alkaline earth metals is ns2</u>
Answer:
Answer D. Picture II shows a chemical change, because the same substance changes form
Explanation:
This is the temperature that water molecules slow down enough to stick to each other and form a solid crystal
The incorrect rule for assigning oxidation numbers is Hydrogen is usually –1.
Hydrogen is usually +1
<h3>What is oxidation number?</h3>
Oxidation numbers can be defined as that number which is assigned to an element in chemical reaction which represents the number of electrons lost or gained.
So therefore, the incorrect rule for assigning oxidation numbers is Hydrogen is usually –1.
Learn more about oxidation numbers:
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Answer:
Explanation:
The formula of the reaction:
KClO₂ → KCl + O₂
To assign oxidation numbers, we have to obey some rules:
- Elements in an uncombined state or one whose atoms combine with one another to form molecules have an oxidation number of zero.
- The charge on simple ions signifies their oxidation number.
- The algebraic sum of all the oxidation number of all atoms in a neutral compound is zero. For radicals with charges, their oxidation number is the charge.
The oxidation number of K in KClO₂:
K + (-1) + 2(-2) = 0
K-5 = 0
K = +5
The oxidation number of K in KCl:
K + (-1) = 0
K = +1
The oxidation number Cl in KClO₂ is -1
For Cl in KCl, the oxidation number is -1
For O in KClO₂, the oxidation number is (2 x -2) = -4
For O in O₂, the oxidation number is 0
K moves from an oxidation state of +5 to +1. This is a gain of electrons and K has undergone reduction. We then say K is reduced.
O moves from an oxidation state of -4 to 0. This is a loss of electrons and O has undergone oxidation. We say O is oxidized.
